use strict;
use warnings;
use File::Slurp;

my @files;    # Array of all file names in the folder.

if($ARGV[0])
{
  @files = read_dir($ARGV[0]);
}
else
{
  @files = read_dir(".");
}

for my $file (@files)
{
  print $file;
  if(-f $file)
  {
    print " is a file.\n";
  }
  else
  {
    print " is a dir.\n";
  }
}

##</code><code>##

file1.txt
filetest.pl
folder -> file2.txt
          file3.txt

##</code><code>##

file1.txt is a file.
filetest.pl is a file.
folder is a dir.

##</code><code>##

file2.txt is a dir.
file3.txt is a dir.